This invention relates to a method of transmitting a video signal at a higher line standard over a transmission channel for signals at a lower standard, and to transmitting and receiving apparatus for use in the method.
Various methods have been proposed for transmitting high definition images, at a reduced bandwidth, but at the same basic line rate as is used for source and display. One example of this type of system is NHK's "MUSE", which operates entirely at 1125 lines. Other techniques have been proposed for packing extra spatial detail, but usually less than is claimed for HDTV ("high-definition television"), into a standard channel such as C-MAC or D2-MAC. These two approaches are described respectively the following papers, (1) Ninomaya, Y. et al. 1984. A single Channel HDTV Broadcast System - The Muse. NHK Laboratory Note No 304, and (2) Arragon, J-P. et al. 1986. Transmission d'images de Television a Haut Definition Compatible avec le Standard D2-MAC Paquet. Acta Electronica 27,1-2.